题目描述
Problem Statement
There are an integer N and M pairs of integers: $(a_1, b_1), (a_2, b_2), \dots, (a_M, b_M). Each pair (a_i, b_i) satisfies 1 \leq a_i \lt b_i \leq N$.
Initally, you have all N! permutations of $(1,2,\dots,N)$.
You will perform M operations. The i-th operation is as follows.
- Do the following for each of your N! permutations.
- Compare the a_i-th and b_i-th elements. If the former is greater, swap the two elements.
For each $1 \leq i \leq M$, let S_i be the number of permutations of yours that are already sorted in ascending order at the end of the i-th operation.
Print $S_1, S_2, \dots, S_M$.
Here, the input gives you pairs of integers (x_i, y_i) instead of (a_i, b_i).
The values of (a_i, b_i) can be obtained using x_i, y_i, and S_{i-1} as follows. (Let S_0 = 1 for convenience.)
- Let $c_i = ((x_i + S_{i-1}) \bmod N) + 1$.
- Let $d_i = ((y_i + S_{i-1} \times 2) \bmod N) + 1.$ (Here, it is guaranteed that $c_i \neq d_i.)$
- Let $a_i = \min(c_i, d_i)$.
- Let $b_i = \max(c_i, d_i)$.
Input
The input is given from Standard Input in the following format:
N M
x_1 y_1
x_2 y_2
$\vdots$
x_M y_M
Output
Print M lines. The i-th line should contain S_i.
Constraints
- $2 \leq N \leq 15$
- $1 \leq M \leq 5 \times 10^5$
- $1 \leq a_i \lt b_i \leq N$
- $0 \leq x_i, y_i \leq N - 1$
Sample Input 1
2 1
1 1
Sample Output 1
2
You start with the permutations (1, 2) and (2, 1).
We have (a_1, b_1) = (1, 2). At the end of the first operation, you have two copies of (1, 2), so you should print 2.
Sample Input 2
3 4
0 1
2 1
1 1
0 1
Sample Output 2
2
4
4
6
(a_i, b_i) in order are (1, 2), (2, 3), (1, 3), (1, 2).
Sample Input 3
5 5
4 4
0 4
1 1
2 4
1 2
Sample Output 3
2
4
4
8
16
(a_i, b_i) in order are (1, 2), (3, 4), (1, 5), (2, 3), (4, 5).
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分